Question : Powerchute will not recognize other devices

I have installed an APC3000 Smart-UPS.
It came with Powerchute Business Edition Basic.
I have 3 Windows 2003 servers attached to this UPS.

The instructions say to install the Agent on each device plugged into(electrically) the UPS (up to 5).  However, during the installation, it does a search for which COM port UPS is attached to....No problem for the computer which is directly attached via serial cable.  However, when I went to install it on the other devices, the installation did not want to continue if it couldn't find the COM port.

I attempted to bypass this problem, by moving the serial cable to the next computer I installed the agent on, and did the same for the third. Then, I installed the Powerchute Server software on one of the servers.

I was able to get the Powerchute device list to discover the the computer directly connected to the UPS.  However, my bypass must not have been the right answer, because I can't get it to find the other two computers which are plugged in (electrically) but have no communication port attached to the UPS. All these computers are on the same network segment (172.20.20.x).  

Does anyone know how this software talks to all the machines the agent is installed on?

Answer : Powerchute will not recognize other devices

The software you are given free with the UPS is limited to monitoring five devices.  Their pro version which costs $ is unlimited.
Think about it, how would the mesage that the UPS is on battery get to a computer if there was no signal cable between the two?  There is no such thing as a computer power supply that reads signals from the power cord and the UPS doesn't put signals on it's power output.  As for the computers being networked, how would one computer know what it is plugged into?  If it doesn't know what it is plugged into, how would it know that it is about to lose power unless it got a signal from it's power source?